PLEASE MEASURE PETS NECK CIRCUMFERENCE FIRSTLY BEFORE ORDERING,A LITTLE BIGGER SIZE WILL BE MORE COMFORTABLE FOR YOUR PETS! This Medium size 5 E-collar come out from size 6, this size is suitable for most adult cats which is weight over 11 lbs, and small dog like pomeranian and Shih Tzu. How to properly determine size: To find the right size collar, you will need TWO measurements. 1) Neck circumference, use a soft tape measure or piece of string and wrap it snugly around the base of your dog’s neck-snug enough so that you cannot fit any fingers under the measuring tape. 2) The size in inches from the neck to the snout. If any of the measurements are 'between' two sizes, choose the larger size. Material: Plastic + Flannel, Size: Depth/ Width: 4.9 IN, Neck Circumference: 7.0-8.8 IN. Features: 1. PVC, Quality and Reliable 2. Lightweight, Washable, Scratch and Bite-resistant 3. Multi-function, great for recovery from injuries, rashes and post surgery 4. Reliable and practical, recommended for beauty and medical care Note: Please allow 1-2 cm, differs due to manual measurement, the color may be a little different due to the effect of light and different computer displayer.